2011’s most and least fuel-efficient vehicles

Here’s a look at some of the winners and losers when it comes to fuel efficiency, based on government data.

Brian Carolin, senior vice president of sales and marketing for Nissan North America, holds the trophy for the Nissan Leaf after it was announced as the 2011 World Car of the Year at the New York International Auto Show on April 21. The Leaf is considered the most fuel-efficient vehicle, according to government data. The electric car gets the equivalent of 99 miles per gallon in the combined city-highway driving. For the all-electric Leaf, the mpg equivalent represents the miles per amount of energy used that is equivalent to the energy in a gallon of gas.Richard Drew/AP